Brown mussels Perna perna were exposed to cadmium Cd, lead Pb, and copper Cu concentrations under acute exposure and exposure-depuration tests for the estimation of biochemical biomarker catalase CAT. The acute tests showed accumulated Cd, Pb, and Cu in Perna perna correlated linearly with the exposure concentrations , , and for Cd, Pb, and Cu, resp

The results of CAT increased significantly in tissues of treatment mussels after 72 h exposure when compared to control. The values of total protein were disturbed in exposed groups when compared with control. These results suggest that metabolites and catalase activity were affected by heavy metal exposures. Analysis using the Spearman rank correlation coefficient showed that the CAT activity appeared to have a significant positive correlativity , , and for Cd, Pb, and Cu, resp. with the accumulated Cd, Pb, and Cu concentrations, respectively. The result of exposure-depuration tests showed that there is a general tendency for CAT to decrease in depuration phase, suggesting that the induction of catalase is metal and-or mixture of metals dependent.